Solid solution and densification behavior of zirconium oxycarbide (ZrCxOy) ceramics via doping ZrO2 and Zr in ZrC

zirconium oxycarbide (ZrCxOy) ceramics were hot pressed using ZrC-5ZrO2 and ZrC-5ZrO2-5Zr (number in mol%) mixtures as starting powders, and the solid solution and densification processes were investigated. When 5 mol% ZrO2 were added to ZrC matrix, ZrCxOy and CO were formed during the reaction between ZrC and ZrO2 occurred above 1600 °C. And the sintered ZrCxOy ceramic had numerous pores. However, the co-doping of ZrO2 and Zr could reduce the reaction temperatures and CO amounts in ZrC-5ZrO2-5Zr system, resulting in a near fully dense ZrCxOy ceramic. The chemical composition of obtained ZrCxOy ceramics were also calculated according to oxygen content and reaction processes.